<PAGE>

Exhibit 10.10


THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS 
AMENDED (THE "ACT") OR THE SECURITIES LAWS OF ANY STATE. THIS WARRANT MAY NOT 
BE SOLD, PLEDGED, TRANSFERRED, ASSIGNED OR OTHERWISE DISPOSED OF IN THE 
ABSENCE OF SUCH REGISTRATION OR AN EXEMPTION THEREFROM UNDER PROVISIONS OF 
THE FEDERAL ACT AND ALL APPLICABLE STATE SECURITIES LAWS.

Right to Purchase Shares of Common Stock of Zycad Corporation
August 21, 1997

-------------------------

Common Stock Purchase Warrant

       ZYCAD CORPORATION, a Delaware corporation (the "Company"), hereby 
certifies that for $10.00 and other good and valuable consideration, the 
receipt and sufficiency of which are hereby acknowledged, Halifax Fund, L.P., 
having an address at c/o Citco Fund Services Ltd., Corporate Centre, West Bay 
Road, P.O. Box 31106, SMB, Grand Cayman, Cayman Islands ("Purchaser") or any 
other Warrant Holder is entitled, on the terms and conditions set forth 
below, to purchase from the Company at any time beginning after the date 
hereof and ending thirty-six (36) months after the date hereof One Hundred 
and Twenty Two Thousand and Five Hundred (122,500) shares of fully paid and 
nonassessable shares of Common Stock, $.10 par value, of the Company (the 
"Common Stock"), at a purchase price per share of Fifty Three and One 
Hundred Twenty Five Thousand Cents (U.S. $.53125) per share of Common Stock 
(the "Purchase Price"), as the same may be adjusted pursuant to Section 5 
herein.

1.     DEFINITIONS.

       (a) the term "Warrant Holder" shall mean the Purchaser or any assignee 
of all or any portion of this Warrant at any given time who, at the time of 
assignment, acquired the right to purchase at least 2,000 Warrant Shares, 
(such number being subject to adjustment after the date hereof pursuant to 
Section 5 herein.)

       (b) the term "Warrant Shares" shall mean the Shares of Common Stock or 
other securities issuable upon exercise of this Warrant.

       (c) other terms used herein which are defined in the Convertible 
Securities Subscription Agreement (the "Agreement") or the Registration 
Rights Agreement (the "Registration Rights Agreement"), both dated February 
13, 1997 between the Company and the Purchaser, shall have the same meanings 
herein as therein.

       2.     EXERCISE OF WARRANT.  This Warrant may be exercised by 
the Warrant Holder, in whole or in part, at any time and from time to time by 
surrender of this Warrant, together with the form of subscription at the end 
hereof duly executed by Warrant Holder, to the Company at its principal 
office. In the event that the Warrant is not exercised in full, the number of 
Warrant Shares shall be reduced by the number of such Warrant Shares for 
which this Warrant is exercised, and the Company, at its expense, shall 
forthwith issue and deliver to or upon the order of Warrant Holder a new 
Warrant of like tenor in the name of Warrant Holder or as Warrant Holder 
(upon payment by Warrant Holder of any applicable transfer taxes) may 
request, reflecting such adjusted Warrant Shares. 

       If, despite the Company's obligations provided in Paragraphs 4(a) and 
4(d) hereof, the Company shall not have registered pursuant to a Registration 
Statement under the Act and/or available for issuance upon exercise of this 
Warrant sufficient shares of Common Stock for such issuance as such 
registered shares then, notwithstanding anything contained herein to the 
contrary and in addition to and not in lieu of any of the other rights and 
remedies to which the Warrant Holder may be entitled by reason of the 
Company's failure fully to meet its obligations under Paragraphs 4(a) and 
4(d)


<PAGE>

hereof, the Warrant Holder may, at its election exercised in its sole 
discretion, exercise this Warrant in whole or in part and, in lieu of making 
the cash payment otherwise contemplated to be made to the Company upon such 
exercise in payment of the Purchase Price, elect instead to receive upon such 
exercise the Net Number of shares of Common Stock determined according to the 
following formula:

       Net Number  =  (A x B)  -  (A x C)
                      -------------------
                                     B
              For purposes of the foregoing formula:    

                     A = the total number of shares with respect to which this 
                         Warrant is then being exercised.

                     B = the fair market value of a share of Common Stock at 
                         the time of such calculation, as determined
                         in accordance with Paragraph 3(b) hereof. 
       
                     C = the Purchase Price then in effect at the time of such
                         exercise.

       3.     DELIVERY OF STOCK CERTIFICATES.

              (a)    Subject to the terms and conditions of this Warrant, as 
soon as practicable after the exercise of this Warrant in full or in part, 
and in any event within five (5) days thereafter, the Company at its expense 
(including, without limitation, the payment by it of any applicable issue 
taxes) will cause to be issued in the name of and delivered to Warrant 
Holder, or as Warrant Holder (upon payment by Warrant Holder of any 
applicable transfer taxes) may lawfully direct, a certificate or certificates 
for the number of fully paid and non-assessable shares of Common Stock to 
which Warrant Holder shall be entitled on such exercise, together with any 
other stock or other securities or property (including cash, where 
applicable) to which Warrant Holder is entitled upon such exercise.

              (b)    This Warrant may not be exercised as to fractional 
shares of Common Stock.  In the event that the exercise of this Warrant, in 
full or in part, would result in the issuance of any fractional share of 
Common Stock, then in such event Warrant Holder shall be entitled to cash 
equal to the fair market value of such fractional share.  For purposes of 
this Warrant, fair market value shall equal the closing trading price of the 
Common Stock on the Nasdaq Stock Market, the American Stock Exchange or the 
New York Stock Exchange, whichever is the principal trading exchange or 
market for the Common Stock (the "Principal Market") on the date of 
determination or, if the Common Stock is not listed or admitted to trading on 
any national securities exchange or quoted in the Nasdaq Stock Market, the 
average of the closing bid and asked prices on the over-the-counter market as 
furnished by any New York Stock Exchange member firm reasonably selected from 
time to time by the Company for that purpose, or, if the Common Stock is not 
listed or admitted to trading on any national securities exchange or quoted 
on the Nasdaq Stock Market or traded over-the-counter and the average price 
cannot be determined a contemplated above, the fair market value of the 
Common Stock shall be as reasonably determined in good faith by the Company's 
Board of Directors.

       4.     COVENANTS OF THE COMPANY.

              (a)    The Company shall use its reasonable best efforts to 
insure that a Registration Statement under the Act covering the issuance of 
the Warrant Shares and the resale or other disposition thereof by Warrant 
Holder is effective as provided in its Registration Rights Agreement.

              (b)    The Company shall take all necessary action and 
proceedings as may be required and permitted by applicable law, rule and 
regulation, including, without limitation the notification of the Nasdaq 
Stock Market, for the legal and valid issuance of this Warrant and the 
Warrant Shares to the Warrant Holder under this Warrant.

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<PAGE>

              (c)    From the date hereof through the last date on which this 
Warrant is exercisable, the Company shall take all steps reasonably necessary 
and within its control to insure that the Common Stock remains listed on the 
Principal Market and shall not amend its Certificate of Incorporation or 
Bylaws so as to adversely affect any rights of the Warrant Holder under this 
Warrant.

              (d)    The Company shall at all times reserve and keep 
available, solely for issuance and delivery as Warrant Shares hereunder, such 
shares of Common Stock as shall from time to time be issuable.

              (e)    The Warrant Shares, when issued in accordance with the 
terms hereof, will be duly authorized and, when paid for or issued in 
accordance with the terms hereof, shall be validly issued, fully paid and 
non-assessable. The Company has authorized and reserved for issuance to 
Warrant Holder the requisite number of shares of Common Stock to be issued 
pursuant to this Warrant.

       (f)    With a view to making available to Warrant Holder the benefits 
of Rule 144 promulgated under the Act and any other rule or regulation of the 
SEC that may at any time permit Warrant Holder to sell securities of the 
Company to the public without registration, the Company agrees to use its 
reasonable best efforts to:

(i)    make and keep public information available, as those terms are 
understood and defined in Rule 144, at all times;

(ii)   file with the SEC in a timely manner all reports and other documents 
required of the Company under the Act and the Exchange Act; and

(iii)  furnish to any Warrant Holder forthwith upon request a written 
statement by the Company that it has complied with the reporting requirements 
of Rule 144 and of the Act and the Exchange Act, a copy of the most recent 
annual or quarterly report of the Company, and such other reports and 
documents so filed by the Company as may be reasonably requested to permit 
any such Warrant Holder to take advantage of any rule or regulation of the 
SEC permitting the selling of any such securities without registration.

       5.     ADJUSTMENT OF EXERCISE PRICE AND NUMBER OF SHARES.  The number 
of and kind of securities purchasable upon exercise of this Warrant and the 
Purchase Price shall be subject to adjustment from time to time as follows:

              (a)    SUBDIVISIONS, COMBINATIONS AND OTHER ISSUANCES.  If the 
Company shall at any time after the date hereof but prior to the expiration 
of this Warrant subdivide its outstanding securities as to which purchase 
rights under this Warrant exist, by split-up, spin-off, or otherwise, or 
combine its outstanding securities as to which purchase rights under this 
Warrant exist, the number of Warrant Shares as to which this Warrant is 
exercisable as of the date of such subdivision, split-up, spin-off or 
combination shall forthwith be proportionately increased in the case of a 
subdivision, or proportionately decreased in the case of a combination.  
Appropriate adjustments shall also be made to the purchase price payable per 
share, but the aggregate purchase price payable for the total number of 
Warrant Shares purchasable under this Warrant as of such date shall remain 
the same.

              (b)    STOCK DIVIDEND.  If at any time after the date hereof 
the Company declares a dividend or other distribution on Common Stock payable 
in Common Stock or other securities or rights convertible into Common Stock 
("Common Stock Equivalents") without payment of any consideration by holders 
of Common Stock for the additional shares of Common Stock or the Common Stock 
Equivalents (including the additional shares of Common Stock issuable upon 
exercise or conversion thereof), then the number of shares of Common Stock 
for which this Warrant may be exercised shall be increased as of the record 
date (or the date of such dividend distribution if no record date is set) for 
determining which holders of Common Stock shall be entitled to receive such 
dividends, in proportion to the increase in the number of outstanding shares 
(and shares of Common Stock issuable upon conversion of all such securities 
convertible into Common Stock) of Common Stock as a result of such dividend, 
and the Purchase Price shall be adjusted 

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<PAGE>

so that the aggregate amount payable for the purchase of all the Warrant 
Shares issuable hereunder immediately after the record date (or on the date 
of such distribution, if applicable), for such dividend shall equal the 
aggregate amount so payable immediately before such record date (or on the 
date of such distribution, if applicable).

              (c)    OTHER DISTRIBUTIONS.  If at any time after the date 
hereof the Company distributes to holders of its Common Stock, other than as 
part of its dissolution, liquidation or the winding up of its affairs, any 
shares of its capital stock, any evidence of indebtedness or any of its 
assets (other than cash, Common Stock or securities convertible into Common 
Stock), then the Company shall decrease the per share Purchase Price of this 
Warrant by an appropriate amount based upon the value distributed on each 
share of Common Stock as determined in good faith by the Company's Board of 
Directors.

              (d)    MERGER, ETC.  If at any time after the date hereof 
there shall be a merger or consolidation of the Company with or into or a 
transfer of all or substantially all of the assets of the Company to another 
entity, then the Warrant Holder shall be entitled to receive upon such 
transfer, merger or consolidation becoming effective, and upon payment of the 
aggregate Purchase Price then in effect, the number of shares or other 
securities or property of the Company or of the successor corporation 
resulting from such merger or consolidation, which would have been received 
by Warrant Holder for the shares of stock subject to this Warrant had this 
Warrant been exercised just prior to such transfer, merger or consolidation 
becoming effective or to the applicable record date thereof, as the case may 
be.

              (e)    RECLASSIFICATION, ETC.  If at any time after the date 
hereof there shall be a reorganization or reclassification of the securities 
as to which purchase rights under this Warrant exist into the same or a 
different number of securities of any other class or classes, then the 
Warrant Holder shall thereafter be entitled to receive upon exercise of this 
Warrant, during the period specified herein and upon payment of the Purchase 
Price then in effect, the number of shares or other securities or property 
resulting from such reorganization or reclassification, which would have been 
received by the Warrant Holder for the shares of stock subject to this 
Warrant had this Warrant at such time been exercised.

              (f)    PURCHASE PRICE ADJUSTMENT.  In the event that the 
Company issues or sells any Common Stock or securities which are convertible 
into or exchangeable for its Common Stock or any convertible securities, or 
any warrants or other rights to subscribe for or to purchase or any options 
for the purchase of its Common Stock or any such convertible securities 
(other than shares or options issued or which may be issued pursuant to the 
Company's employee or director option plans or shares issued upon exercise of 
options, warrants or rights outstanding on the date of the Agreement and 
listed in the Exchange Act Reports) at an effective purchase price per share 
which is less than the Purchase Price then in effect or the fair market value 
(as hereinabove defined) of the Common Stock on the trading day next 
preceding such issue or sale, then in each such case, the Purchase Price in 
effect immediately prior to such issue or sale shall be reduced effective 
concurrently with such issue or sale to an amount determined by multiplying 
the Purchase Price then in effect by a fraction, (x) the numerator of which 
shall be the sum of (1) the number of shares of Common Stock outstanding 
immediately prior to such issue or sale, including, without duplication, 
those deemed to have been issued under any provision of the Debentures and 
the Warrants plus (2) the number of shares of Common Stock which the 
aggregate consideration received by the Company for such additional shares 
would purchase at such fair market value or Purchase Price, as the case may 
be, then in effect; and (y) the denominator of which shall be the number of 
shares of Common Stock of the Company outstanding immediately after such 
issue or sale including, without duplication, those deemed to have been 
issued under any provision of the Debentures and Warrants.  For purposes of 
the foregoing fraction, Common Stock outstanding shall include, without 
limitation, any Equity Offerings (as defined in the Debentures) then 
outstanding, whether or not they are exercisable or convertible when such 
fraction is to be determined.

       In the event of any such issuance for a consideration which is less 
than such fair market value and also less than the Purchase Price then in 
effect, then there shall be only one such adjustment by reason of such 
issuance, such adjustment to be that which results in the greatest reduction 
of the Purchase Price computed as aforesaid.  The number of shares which may 
be purchased hereunder shall be increased proportionately to any reduction in 
Purchase Price 

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<PAGE>

pursuant to this paragraph 5(f), so that after such adjustments the aggregate 
Purchase Price payable hereunder for the increased number of shares shall be 
the same as the aggregate Purchase Price in effect just prior to such 
adjustments.

       6.     NO IMPAIRMENT.  The Company will not, by amendment of its 
Certificate of Incorporation or through any reorganization, transfer of 
assets, consolidation, merger, dissolution, issue or sale of securities or 
any other voluntary action, avoid or seek to avoid the observance or 
performance of any of the terms of this Warrant, but will at all times in 
good faith assist in the carrying out of all such terms and in the taking of 
all such action as may be necessary or appropriate in order to protect the 
rights of the Warrant Holder against impairment.  Without limiting the 
generality of the foregoing, the Company (a) will not increase the par value 
of any Warrant Shares above the amount payable therefor on such exercise, and 
(b) will take all such action as may be reasonably necessary or appropriate 
in order that the Company may validly and legally issue fully paid and 
nonassessable Warrant Shares on the exercise of this Warrant.  

       7.     NOTICE OF ADJUSTMENTS; NOTICES.  Whenever the Purchase Price or 
number of Shares purchasable hereunder shall be adjusted pursuant to Section 
5 hereof, the Company shall execute and deliver to the Warrant Holder a 
certificate setting forth, in reasonable detail, the event requiring the 
adjustment, the amount of the adjustment, the method by which such adjustment 
was calculated and the Purchase Price and number of shares purchasable 
hereunder after giving effect to such adjustment, and shall cause a copy of 
such certificate to be mailed (by first class mail, postage prepaid) to the 
Warrant Holder.

       8.     RIGHTS AS STOCKHOLDER.  Prior to exercise of this Warrant, the 
Warrant Holder shall not be entitled to any rights as a stockholder of the 
Company with respect to the Warrant Shares, including (without limitation) 
the right to vote such shares, receive dividends or other distributions 
thereon or be notified of stockholder meetings.  However, in the event of any 
taking by the Company of a record of the holders of any class of securities 
for the purpose of determining the holders thereof who are entitled to 
receive any dividend (other than a cash dividend) or other distribution, any 
right to subscribe for, purchase or otherwise acquire any shares of stock of 
any class or any other securities or property, or to receive any other right, 
the Company shall mail to each Warrant Holder, at least 10 days prior to the 
date specified therein, a notice specifying the date on which any such record 
is to be taken for the purpose of such dividend, distribution or right, and 
the amount and character of such dividend, distribution or right.

       9.     REPLACEMENT OF WARRANT.  On receipt of evidence reasonably 
satisfactory to the Company of the loss, theft, destruction or mutilation of 
the Warrant and, in the case of any such loss, theft or destruction of the 
Warrant, on delivery of an indemnity agreement or security reasonably 
satisfactory in form and amount to the Company or, in the case of any such 
mutilation, on surrender and cancellation of such Warrant, the Company at its 
expense will execute and deliver, in lieu thereof, a new Warrant of like 
tenor.

       10.    SPECIFIC ENFORCEMENT; CONSENT TO JURISDICTION.

                     (a)  The Company and the Warrant Holder acknowledge and 
agree that irreparable damage would occur in the event that any of the 
provisions of this Warrant were not performed in accordance with their 
specific terms or were otherwise breached.  It is accordingly agreed that the 
parties shall be entitled to an injunction or injunctions to prevent or cure 
breaches of the provisions of this Warrant and to enforce specifically the 
terms and provisions hereof, this being in addition to any other remedy to 
which either of them may be entitled by law or equity.

                     (b)  Each of the Company and the Warrant Holder 
(i) hereby irrevocably submits to the exclusive jurisdiction of the United 
States District Court for the Southern District of New York for the purposes 
of any suit, action or proceeding arising out of or relating to this Warrant 
and (ii) hereby waives, and agrees not to assert in any such suit, action or 
proceeding, any claim that it is not personally subject to the jurisdiction 
of such court, that the suit, action or proceeding is brought in an 
inconvenient forum or that the venue of the suit, action or proceeding is 
improper.  Each of the Company and the Warrant Holder consents to process 
being served in any such suit, action or proceeding by mailing a copy thereof 
to such party at the address in effect for notices to it under this Warrant 
and agrees that such 

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<PAGE>

service shall constitute good and sufficient service of process and notice 
thereof.  Nothing in this paragraph shall affect or limit any right to serve 
process in any other manner permitted by law.

       11.    ENTIRE AGREEMENT; AMENDMENTS.  This Warrant, the Exhibits 
hereto and the provisions contained in the Agreement, the Registration Rights 
Agreement or the Debentures and incorporated into this Warrant and the 
Warrant Shares contain the entire understanding of the parties with respect 
to the matters covered hereby and thereby and, except as specifically set 
forth herein and therein, neither the Company nor the Warrant Holder makes 
any representation, warranty, covenant or undertaking with respect to such 
matters.  No provision of this Agreement may be waived or amended other than 
by a written instrument signed by the party against whom enforcement of any 
such amendment or waiver is sought.
       
       12.    RESTRICTED SECURITIES.  Sections 4.5, 5.1, 5.2 and 5.3 of the 
Agreement are incorporated herein by reference and hereby made a part hereof.

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<PAGE>

       13.    NOTICES.  Any notice or other communication required or 
permitted to be given hereunder shall be in writing and shall be effective 
(a) upon hand delivery or delivery by telex (with correct answer back 
received), telecopy or facsimile at the address or number designated below 
(if delivered on a business day during normal business hours where such 
notice is to be received), or the first business day following such delivery 
(if delivered other than on a business day during normal business hours where 
such notice is to be received) or (b) on the second business day following 
the date of mailing by express courier service, fully prepaid, addressed to 
such address, or upon actual receipt of such mailing, whichever shall first 
occur.  The addresses for such communications shall be:

              to the Company:

Zycad Corporation
47100 Bayside Parkway
Fremont, California 94538

Attn: 
Fax:  (510) 623-4575

              with copies to:

Wilson, Sonsini, Goodrich & Rosati
650 Page Mill Road
Palo Alto, California 94304-1050

Attn:  
Fax:  

              to the Warrant Holder:
                            
Halifax Fund, L.P.
c/o Citco Fund Services Ltd.
Corporate Centre, West Bay Road
P.O. Box 31106
SMB, Grand Cayman, Cayman Islands, BWI    

Attn:  
Fax:  

              with copies to:

The Palladin Group
40 W. 57th Street, Suite 1500
New York, NY 10019

Attn:  Andrew Kaplan
Fax:   (212) 698-0599

Copies of all notices to the Company or to the Warrant Holder shall also be
provided to:

                            Promethean Investment Group, L.L.C.
                            40 West 57th Street, Suite 1520

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<PAGE>

                            New York, NY  10019

                            Attn:  James F. O'Brien, Jr.
                            Fax:   (212) 698-0505

                            GOULSTON & STORRS
                            400 Atlantic Avenue
                            Boston, MA  02110-3333

                            Attn:  Richard Langerman, Esq.
                            Fax:   (617) 574-4112

Either party hereto may from time to time change its address for notices 
under this Section 13 by giving at least 10 days prior written notice of such 
changed address to the other party hereto.

       14.    MISCELLANEOUS.  This Warrant and any term hereof may be 
changed, waived, discharged or terminated only by an instrument in writing 
signed by the party against which enforcement of such change, waiver, 
discharge or termination is sought.  This Warrant shall be construed and 
enforced in accordance with and governed by the laws of the State of New 
York.  The headings in this Warrant are for purposes of reference only, and 
shall not limit or otherwise affect any of the terms hereof.  The invalidity 
or unenforceability of any provision hereof shall in no way affect the 
validity or enforceability of any other provision.

       15.    EXPIRATION.  The right to exercise this Warrant shall expire 
thirty-six (36) months after the date hereof.

[Signatures on next page.]

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<PAGE>

Dated as of: August 21, 1997       ZYCAD CORPORATION


By:   /s/ Phillips W. Smith
         
Title:   President and CEO

[CORPORATE SEAL]

Attest:

By:   /s/ Douglas E. Klint
Its:  Vice President, Secretary and 
        General Counsel

Halifax Fund, L.P.

By: The Palladin Group
Its:  Investment Adviser

By:  /s/ Andrew Kaplan 
Its:  Vice President

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<PAGE>

FORM OF WARRANT EXERCISE
(TO BE SIGNED ONLY ON EXERCISE OF WARRANT)

TO _____________________________

       The undersigned, the holder of the within Warrant, hereby irrevocably
elects to exercise this Warrant for, and to purchase thereunder, _________
shares of Common Stock of ZYCAD CORPORATION, a Delaware corporation (the
"Company"), and herewith makes payment of $__________ therefor, and requests
that the certificates for such shares be issued in the name of, and delivered
to _________________, whose address is __________________.

Dated:
       ----------------------------------------
       (Signature must conform to name of holder as specified on the face of
the Warrant)

       ----------------------------------------
       (Address)

                                       Tax Identification Number:_____________


-----------------


FORM OF ASSIGNMENT
(TO BE SIGNED ONLY ON TRANSFER OF WARRANT)

For value received, the undersigned hereby sells, assigns, and transfers unto 
_________________ the right represented by the within Warrant to purchase 
_____________ shares of Common stock of ZYCAD CORPORATION, a Delaware 
corporation, to which the within Warrant relates, and appoints 
_________________ Attorney to transfer such right on the books of ZYCAD 
CORPORATION, a Delaware corporation, with full power of substitution the 
premises.

Dated:
       -----------------------------------
       (Signature must conform to name of holder as specified on the face of
the Warrant)

       -----------------------------------
       (Address)

Signed in the presence of:

--------------------------------

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